Electronic devices and components that are designed for high frequency data communication applications have numerous applications. One common practical application for such devices and components is cellular telephony systems. In this regard, the need for component integration has become progressively more important for increasingly miniaturized high performance cellular phones with advanced features.
Cellular phone high power amplifier stations use matching circuits and power amplification circuits to match the impedances in a relatively weak cellular telephone signal and to amplify and transmit the signal. The LDMOS power amplification system illustrated in FIG. 1 is one in-package power amplification system that successfully incorporates passive elements, including passive inductors and capacitors, in a highly integrated impedance matching network. The illustrated power amplification system 100 includes a metal flange 102 that functions as a support and as an electrical ground. A ceramic substrate 104 is formed on the metal flange 102 and insulates the flange 102 from the power amplification circuitry, which includes a gate lead 106, a drain lead 108, and an array of inductor bond wires 114 that connect matching capacitors 110 and active devices 112.
FIG. 2 is a circuit diagram for a power amplifier (PA) system. The equivalent circuit schematics for the assembly represented in FIG. 1 is shown in box 200. Box 210 represents a large capacitance in series with a small inductance, which together realize the shunt LC matching network. This part of the MOSCAP matching network includes long bond wires that connect the MOSCAP die to the LDMOS output drain, which is located on a base station power amplifier die. The bond wires are commonly assembled with a height of approximately 45 mils (˜1.1 mm) in order to realize an appropriate inductance value. The bond wire length for this assembly creates difficulties when assembling and operating the power amplifier. Slack bond wire is difficult to control during manufacturing. Further, longer bond wires become hotter and less reliable during operation than shorter bond wires, and also cause relatively wide inductance variations.
One of the most significant parameters for evaluating the performance of a shunt matching network is the network's Q factor. The Q factor refers to the measure of quality of a particular frequency response, and is correlated with a storage:loss ratio. The simulated Q factor for the current bond wire+MOSCAP system is about 60, although 60 is toward the lower end of the range of acceptable Q factors for the shunt LC matching network.
Accordingly, it is desirable to provide a shunt LC matching network having a Q factor that is higher than 60 and that can be manufactured with efficiency. It is also desirable for the matching network to utilize quality passive devices in order for the matching network to be easily controlled during manufacturing, and to have a relatively low parts count. It is also desirable for such a matching network to have improved reliability. Furthermore, other desirable features and characteristics of the present invention will become apparent from the subsequent detailed description and the appended claims, taken in conjunction with the accompanying drawings and the foregoing technical field and background.